Hydraulic port protection plugs for shock absorbers

Abstract

Hydraulic port protection plugs for insertion into hydraulic ports in a shock absorber to prevent contaminants from entering the shock absorber and residual oil from draining out through the hydraulic ports during storage, shipping, and handling of the shock absorber. The hydraulic port protection plugs comprise a tubular body and a pierceable seal that is configured to receive an inboard portion of a hydraulic fitting. The pierceable seal is designed so that the inboard portion of the hydraulic fitting may be inserted through the pierceable seal of the hydraulic port protection plug and into the hydraulic port in the shock absorber such that the hydraulic port protection plug does not have to be removed and seals the hydraulic fitting within the hydraulic port in the shock absorber in an installed position.

What is claimed is: 
     
         1 . A shock absorber assembly, comprising:
 a shock absorber with a sliding piston that divides the shock absorber into first and second working chambers, a piston rod mounted to the sliding piston, and a lower housing opposite the piston rod;   at least one hydraulic port provided in the lower housing of the shock absorber; and   a hydraulic port protection plug having a tubular body with a geometric configuration that is configured to be insertable into the at least one hydraulic port in the lower housing,   wherein the hydraulic port protection plug includes a pierceable seal that is configured to receive a portion of a hydraulic fitting that is insertable through the pierceable seal of the hydraulic port protection plug and into the at least one hydraulic port in the lower housing such that the hydraulic port protection plug seals the hydraulic fitting within the at least one hydraulic port in the lower housing in an installed position.   
     
     
         2 . The shock absorber assembly of  claim 1 , wherein the tubular body of the hydraulic port protection plug defines a cavity within the hydraulic port protection plug with one open end and an opposite end that is bounded by a pierceable wall. 
     
     
         3 . The shock absorber assembly of  claim 2 , wherein the pierceable seal is a linear slit that extends through the pierceable wall and is arranged in fluid communication with the open-end cavity defined by the tubular body of the hydraulic port protection plug. 
     
     
         4 . The shock absorber assembly of  claim 2 , wherein the pierceable seal is a plurality of linear slits that extend through the pierceable wall in a crisscross arrangement. 
     
     
         5 . The shock absorber assembly of  claim 2 , wherein the pierceable seal is a one-way joker valve with an elastic valve throat that extends into the open-end cavity defined by the tubular body of the hydraulic port protection plug. 
     
     
         6 . The shock absorber assembly of  claim 2 , wherein at least a portion of the pierceable wall is made of a frangible membrane to define a fitting piercing zone at or near a centerline of the hydraulic port protection plug. 
     
     
         7 . The shock absorber assembly of  claim 2 , wherein the pierceable wall has a flat, planar shape in a pre-installed condition of the hydraulic port protection plug. 
     
     
         8 . The shock absorber assembly of  claim 2 , wherein the pierceable wall has a funnel shape with a fitting piercing zone at or near a centerline of the hydraulic port protection plug. 
     
     
         9 . The shock absorber assembly of  claim 2 , wherein the hydraulic port protection plug includes at least one sealing rib that extends circumferentially along an inside surface of the tubular body. 
     
     
         10 . The shock absorber assembly of  claim 9 , wherein the at least one sealing rib is longitudinally spaced from the pierceable wall. 
     
     
         11 . The shock absorber assembly of  claim 9 , wherein the hydraulic port protection plug includes a cap portion that extends radially outward from the tubular body. 
     
     
         12 . The shock absorber assembly of  claim 11 , wherein the pierceable wall is co-planar with the cap portion. 
     
     
         13 . The shock absorber assembly of  claim 11 , wherein the pierceable wall is longitudinally spaced from the cap portion. 
     
     
         14 . A shock absorber assembly, comprising:
 a shock absorber with a sliding piston that divides the shock absorber into first and second working chambers, a piston rod mounted to the sliding piston, and a lower housing opposite the piston rod;   a hydraulic port provided in the lower housing of the shock absorber;   a hydraulic coupling that is configured to mate with the hydraulic port in the lower housing of the shock absorber; and   a hydraulic port protection plug having a tubular body with a geometric configuration that is configured to be insertable into the hydraulic port in the lower housing of the shock absorber,   wherein the hydraulic port protection plug includes a pierceable seal that is configured to receive an inboard portion of the hydraulic coupling such that the hydraulic port protection plug seals the hydraulic fitting within the at least one hydraulic port in the lower housing in an installed position.   
     
     
         15 . The shock absorber assembly of  claim 14 , wherein the hydraulic port in the lower housing includes a stepped-bore with a first stepped portion that receives both the hydraulic port protection plug and the inboard portion of hydraulic coupling in the installed position. 
     
     
         16 . The shock absorber assembly of  claim 15 , wherein the stepped-bore of the hydraulic port in the lower housing includes a second stepped portion that receives an inboard end of hydraulic coupling in the installed position and does receive the hydraulic port protection plug. 
     
     
         17 . The shock absorber assembly of  claim 16 , wherein the inboard end of the hydraulic coupling includes an O-ring seal that abuts the second stepped portion in the installed position. 
     
     
         18 . The shock absorber assembly of  claim 14 , wherein the hydraulic coupling is a hydraulic fitting that is connected to a terminal end of a hydraulic line or is integral with the terminal end of the hydraulic line. 
     
     
         19 . A method of assembling a shock absorber assembly of a vehicle suspension system, the method comprising the steps of:
 installing a piston and a piston rod inside a shock absorber housing;   inserting a hydraulic port protection plug into a hydraulic port in the shock absorber housing to place the shock absorber assembly in a shipping and handling configuration;   installing the shock absorber assembly in a vehicle; and   installing a hydraulic fitting in the hydraulic port while the hydraulic port protection plug is positioned in the hydraulic port by pressing at least a portion of the hydraulic fitting through a pierceable seal in the hydraulic port protection plug.   
     
     
         20 . The method according to  claim 19 , further comprising the steps of:
 connecting the hydraulic fitting to a hydraulic line to fluidly connect the hydraulic port of the shock absorber assembly to another shock absorber in the vehicle suspension system; and   charging the shock absorber assembly by supplying hydraulic fluid or hydraulic oil to the hydraulic port via the hydraulic line.